Organosilicon dioxolanes



United States Patent Ofifice 2,846,448 Patented Aug. 5, 1958ORGANOSILICON DIOXOLANES John L. Speier, Pittsburgh, Pa., assignor toDow Corning Corporation, Midland, Mich., a corporation of Michrgan NoDrawing. Application August 15, 1956 Serial No. 604,058

9 Claims. (Cl. 260-41403) This invention relates to certain dioxolancsubstituted organosilicon compounds, i. e. compounds in which at leastsome of the silicon atoms are attached to a radical of the type O-GH:

where m is an integer of from 1-16 inclusive and R" is an alkyl radicalof from 13 inclusive carbon atoms.

It is an object of this invention to provide novel organosiliconcompounds which have new and unusual properties in their own right asfluid and resinous materials. Another object is to provide organosiliconintermediates which are easily converted to aldehyde substitutedorganosilicon compounds, said intermediates being obtainable byeconomical means and in a high yield without resorting to the use ofspecial high pressure equipment. A further object is to provideorganosilicon intermediates which can be easily converted to aldehydesubstituted organosilicon compounds having a wide range of degrees ofsubstitution (i. e. total organic group/ Si ratios).

The products of this invention can take the form of monomers,polymers'or copolymers containing the above defined dioxolanesubstituents. More specifically, the 3 types of products within thescope of this invention take the form of:

(1) Compounds of the formula O-0Hg R0 ,.R'3 ..s1om(om)mo Where R and Rare monovalent hydrocarbon'radicals free of aliphatic unsaturation, R isan alkyl radical of from 1-3 inclusive carbon atoms, n is an integer offrom 03 inclusive, and m is an integer of from 1-16 inclusive.

(2) Organosiloxanes consisting essentially of units of the formula whereR and m are as above defined and x is an integer of from 0-2 inclusive.

(3) Copolyrneric organosiloxanes consisting essentially of the units asdefined in (2) and units of the formula R,SiO

where R is selected from the group consisting of monovalent hydrocarbonradicals and halogenated monovalent hydrocarbon radicals and 5 Baninteger :of from 0-3 inelusive.

The monomeric products of this invention can be obtained by reacting ahydrogenosilane of the formula R ,,SiH(OR),, where R, R, and-n are asabove defined, with a dioxolane of the formula where R" is as abovedefined and z is an integer of from 0-15 inclusive, in the presence ofeither platinum deposited upon finely divided charcoal or chloroplatinicacid as a catalyst. With the former catalyst a reaction temperature ofl00150 C. is preferable, whereas the latter catalyst promotes thereaction at room temperature and the resulting exothermic reaction caneither be allowed to take its own course or can be subjected tooccasional cooling in order to keep the reaction at any desiredconvenient operating temperature.

The polymeric and copolymeric siloxanes of this invention can beprepared by the hydrolysis of any one or more of the above describedmonomeric silanes of this invention which contain at least one of thedefined (OR) radicals attached to each silicon atom, or by thecohydrolysis of any one or more of such monomeric silanes with monomericsilanes of the general formula R ,,SiX where R and y are as abovedefined, and Xis a hydrolyzable radical such as Cl, Br, -.0C H etc.

Monomeric silanes of the latter type are well known, and many arecommercially available materials. Their cohydrolysis with the monomericsilanes of this invention can be carried out by the conventionaltechniques known in the art, with the exception that where the productsof this invention :are desired as final products, acid conditions duringhydrolysis are to be avoided in order to prevent the conversion of thedioxolane group to the corresponding aldehyde. For this reason it ispreferable that the R ,,SiX material be one in which the hydrolyzable Xsubstituent does not yield an acid upon hydrolysis, e. g. an alkoxyradical, amino .group, hydrogen atom, and the like.

The polymers and copolymers of this invention can also be prepared byreacting a polymeric or copolymeric or" ganosiloxane which contains atleast one silicon bonded hydrogen atom per molecule (and in which theorganic radicals will be the same as the R'or R radicals describedabove) with the defined dioxolane of the formula in the presence ofchloroplatinic acid as the catalyst. Best results with the latter typeof reaction can be obtained by employing a disiloxane reactant such aswhich provides a reaction product in which both of the hydrogen atomshavebeen replaced by the particular dioxolane substituent employed. Ifdesired, the latter reaction product can then 'be copolymerized withconventional organosiloxanes by the conventional and well known alkalinecopolymerization techniques. A similar reaction can be carried out withR'SiH as the silane reactant, followed by the hydrolysis of unreactedsilicon bonded hydrogen.

Where platinum deposited upon finely divided charcoal is employed as thecatalyst in the above described reactions, it is preferred that thecatalyst itself contains from about 0.05 to 2 percent by weight ofplatinum. The catalytic mass is then preferably employed in an amount oifrom 0.5 to 2 percent by weight based on the weight of the organosiliconreactants. The chloroplatinic acid catalyst is preferably employed in aconcentration from 1X10- to 1 10- mol per mol of the dioxolane reactant.To facilitate handling the small amounts required, a solution of thelatter catalyst in a solvent (e. g. isopropanol) is preferred.

The R and R radicals in the above described reactants and products aremonovalent hydrocarbon radicals which are free of aliphaticunsaturation. Examples of suitable radicals of this type are alkyl suchas methyl, ethyl, and octadecyl; alkaryl such as tolyl, aralkyl such asbenzyl, cycloaliphatic such as cyclohexyl, and aryl such as phenyl andxenyl. The most preferred R radicals are methyl, ethyl, propyl,isopropyl and phenyl. The most preferred R radicals are methyl, ethyl,and phenyl. As noted previously, the R" radicals are alkyl radicals offrom l-3 inclusive carbon atoms (i. e. methyl, ethyl, propyl, orisopropyl radicals).

The copolymeric organosiloxanes of this invention include those whichcontain not only a mixture of various dioxolane substitutedorganosilicon units, and those which contain not only one or more ofsuch units, but also one or more of the defined units The latter type ofcopolymeric product preferably contains at least 1 mol percent of thedefined dioxolane substituted siloxane units. The R radicals can bemonovalent hydrocarbon radicals and/or halogenated monovalenthydrocarbon radicals. Thus these radicals include not only those whichhave been described above in regard to the R and R radicals, but alsoalkenyl radicals such as vinyl, allyl, octadecenyl, and cyclohexenyl, aswell as halogenated hydrocarbon radicals such as monoor dichlorophenyl,monoor dibromophenyl, tetrafluoroethyl, m,a,a-trifiuorotolyl,tetrabromoxenyl, chlorocyclohexyl, and chlorovinyl radicals. The mostpreferred of the R radicals are methyl, ethyl, and phenyl. It is alsopreferred that in the copolymers containing these conventionalorganosiloxane units, the latter units be present in amounts and informs such that y in the above formula will have an average value offrom 0.5-3 inclusive. In other words, When Si polymeric units arepresent in the copolymer, sufficient R SiO R SiO, or R SiO units shouldbe present so that y has an average value of at least 0.5. It is to beunderstood that the polymers and copolymers of this invention cancontain small amounts (e. g. up to 2 or 3 percent by weight) of siliconbonded hydroxy and/or hydrocarbonoxy radicals, as is conventional inorganosiloxane polymers.

The monomeric organosilanes of this invention are mostly fluid innature, particularly where the organic substituents are of a relativelylow molecular weight. Such materials can be used as lubricants,hydraulic fluids, and the like, and where they contain hydrolyzablesubstituents they can be used as treating agents to render variousmaterials (such as paper, textiles, and masonry) water repellent. Themonomeric silanes are of course also useful as intermediates in theproduction of the polymeric and copolymeric organosiloxanes of thisinvention. The polymers and copolymers can be either fluid or resinousin nature, depending upon the average degree of substitution of organicgroups attached to silicon atoms, the degree of polymerization, and thesize and type of the organic substituents attached to silicon.Ordinarily those materials which have an average of less than about 2total organic groups attached to silicon per silicon atom are resinousin nature and can be used for molding compounds, impregnants, electricalinsulating varnishes and the like.

A major utility of all of the products of this invention lies in thefact that the dioxolane substituents are easily ruptured in the presenceof acids such as sulfuric and hydrochloric to yield the correspondingaldehyde substituted products of the type ESiCH (CH ),,,CHO. Compoundsof the latter type are capable of reacting with phenols to formphenol-aldehyde type resins. Most 4 I y of such aldehyde substitutedcompounds can not be prepared by methods known to the prior art.

The following examples are illustrative only. The symbols Me, Et, Pr andPh are used herein to represent the radicals methyl, ethyl, propyl andphenyl respectively.

Example 1 A mixture of 0.5 mol of 2-vinyl-4-methyl-1,3-dioxolane,

O-CH3 oH=oHo o-c11onu and 0.5 g. of a catalyst consisting of platinumdeposited on finely divided charcoal and which contained 0.06 percentplatinum by weight, was heated to C. Over a period of one hour, 0.56 molof MeSiH(OET) was added to the mixture, during which time thetemperature was maintained at -120 C. When the addition Was complete thereaction mass was heated for an additional 30 minutes at 140 C. Thereaction product was thenfiltered and the filtrate distilled. Theproduct Was obtained in a yield of 66 percent of theoretical, and wasthe compound 2[2-'(diethoxymethylsilyl)ethyl]-4-methyl- 1,3-dioxolane,i. e.

O-CH: Me(EtO)zSiCH CHzOfi o-oncn:

This compound had a boiling point of 126 C. at 15 mm. Hg, n 1.4241, d0.9697. An analysis of the product showed 11.2 percent Si by weight ascompared to the theoretical value of 11.3 percent. When this reaction isduplicated except that MeSiH(OPh) is used as the silane reactant, thecompound is obtained.

Example 2 When 0.56 mol of PhEtSiH(0Pr) and 0.5 mol of the dioxolaneemployed in Example 1 are reacted in the manner of that example, aproduct of the formula O-CH: PhEt(Pr0)StCHCHzC OCHCH: is obtained.

' Example 3 When HSi(OEt) is employed as the silane reactant in theexperiment of Example 1, the product 0-GH (EtOhSlGHgCHzC O-GHCHa isobtained.

Example 4 When 0.55 mol of Me PhsiH is added to 0.5 mol 'of thedioxolane of Example 1 in the presence of 3X10" mol of benzoyl peroxideand the reaction mixture maintained at 100 C. for 16 hours, the compoundo-on,

MBzPhSlOHzCHzCH O-CHCH8 is obtained.

Example 5 When a mixture of 0.55 mol of PhSiI-I and 0.5 mol of UHF-1011Cis heated at 100 C. for 12 hours in the presence of Example9 X mol oft-butyl perbenzoate as a catalyst, the when the com Ound compound p CH/O CH2 PhEt P msxon on Phmsiomomorr 5 r 2 2 H O- HPr HC 3 as produced inExample 2 is diluted with ether and byis obtained. When the latterproduct is mixed with an drolyzed as in Example 7, a disiloxane fluid ofthe formula equal weight of diethyl ether and is then heated with 10CH2O El; 100 g. water contaimng l g. NaOH, an ether solution of asiloxane consisting essentially of units of the for- CHCHZOH f o mulaMeOHO Ph 2 .0 is obtained. When a mixture containing 1 mol of this samesilane and 1 mol of Cl C H (CH )Si(OEt) is hy- PhS][OH2CH2GH 1 drolyzedby the same method and the hydrolyzate is 0OHP equilibrated by heatingit at 160 C. with 0.1 percent by is obtained. weight of powdered KOH, aviscous fluid of the formula oHi-0\ lilt Et /OCH2 I:CHCH2CH2]SIiO(O1:CaH;MeSiO)z%i [CH2CH2CH MeOHO P11 Ph OCHMe is obtained.Example 6 Example 10 A mixture of 1 mol of the dioxolane of Example 1and when a mlxmre contammg 3 mols of 3X10" mol chloroplatinic acid wasprepared. To this mixture was added 0.55 mol of tetramethyldisiloxanc,Me(EEt0)2SiCHzOH GH i. e. Me HSiOSiI-IMe Occasional cooling of thesystem O OHOH was necessary to keep the reaction temperature down to I 3about for a 30 minutg Period The reaction and 2 mols of Me S1OEt 1shydrolyzed and equilibrated product was then distilled and the producttetramethyldiby the method of Example and F ether dlsmled fromsiloxanedfibis (2 ethy1 4 methy1 ladioxolane), the hydrolyzate afterwashmg sald hydrolyzate free of catalyst, at VlSCOllS liquid is obtainedwhich has the average (F0132 formula CHa-O Me o-onom 2 iol: CHCHzCH2SiO:|SiMe5 MeGHO O SihlegCHzOIhC was obtained in a yield of 64 percent ofthe theoretical yield. This product had a boiling point ranging from 134to 139 C. at about 2 mm. Hg, n ranging from Example 11 1.4400 to 1.4420,and d ranging from 0.980 to 0.987. Analysis showed 15.5 percent silicon,which was in exact When a mixture containing 2 mols of agreement withthe theoretical value. O-OH2 Example 7 I Oh iCHwHzOfi h O-CHOH: Whamepmduct 1 mol each of suoam, PhSi(OEt) and MeSi(OEt) and 5 mols ofPhMeSi(OEt) is diluted with ether and Me(EtO)2SiCHqCHiCH cohydrolyzed bythe method of Example 7, the resulting product is a solution in ether ofthe resinous copolymeric organosiloxane containing units of the formulaas obtained in Example 1, is dissolved in an equal weight 011:

of diethyl ether and is then hydrolyzed in an amount of water sufficientto furnish a 100 percent excess of the ol'fislomcmofi theoretical amountnecessary for complete hydrolysis of the ethoxy radicals, there being atrace of Ca(OI-I) sioz PhSiOl-E Mesiom, and PhMeSiO in the molar presentas a catalyst for the hydrolysis, a polymeric siloxane containing unitsof the formula ratio equlvalent to the stamng sllanes' O-GHCHa /O-CH2Example 12 M i[ 2O 2 :I When a mixture of 0.5 mol of a dioxolane havingthe 0--CHOH3 formula is obtained. 0-OH1 Example 8 0H1=CH(OH2)1O When amixture containing equimolar amounts of O-CHCH3 the silane employed inExample 7, PhMeSi(OEt) PhSi(OEt) and MeSi(OEt) is hydrolyzed as in Exand0.5 g. of the platinum catalyst of Example 1 is heated ample 7, aresinous copolymeric organosiloxane is proto C. and 0.55 mol ofMeSiH(OEt) is added thereduced which contains the units 70 to, followedby maintaining the temperature at C.

O CH2 for 30 minutes, a silane of the formula MeSi cmomofi o O OHOHaMe(EtO)zSiCHz(OH2)ioCH PhMeSiO, PhSiO and MeSiO in equimolar amounts.F15 o-oncm 7 is obtained. The hydrolysis of this material by the methodof Example 7 produces the corresponding siloxane.

That which is claimed is: 1. An organosilicon compound selected from thegroup consisting of (1) compounds of the formula -o112(RO)nRE-SiCH2(GH2)mOH I O-CHR" where R and R are monovalent hydrocarbonradicals free of aliphatic unsaturation, R" is an alkyl radical of from1-3 inclusive carbon atoms, n is an integer of from 0-3 inclusive, and mis an integer of from 1-16 inclusive, (2) organosiloxanes consistingessentially of units of the formula O-OH2 R,S1 CH2(CH2)mCH 3 Z OCHR Twhere R, R", and m are as above defined and x is an integer of from 0-2inclusive, and (3) copolymeric organosiloxanes consisting essentially ofthe units as defined in (2) and units of the formula R Si0 where R isselected from the group consisting of monovalent hydrocarbon radicalsand halogenated monovalent hydrocarbon radicals and y is an integer offrom 0-3 inclusive.

2. Organosilicon compounds of the formula where R and R are monovalenthydrocarbon radicals free of aliphatic unsaturation, R" is an alkylradical of from 1-3 inclusive carbon atoms, n is an integer of from 0-3inclusive, and m is an integer of from 1-16 inclusive.

3. Organosilicon compounds of the formula where R is a radical selectedfrom the group consisting of methyl, ethyl and phenyl radicals and n isan integer of from 0-3 inclusive.

4. A compound of the formula 5. Organosiloxanes consisting essentiallyof polymeric units of the formula 8 where R is a monovalent hydrocarbonradical free of aliphatic unsaturation, R is an alkyl radical of froml-3 inclusive carbon atoms, In is an integer of from l-l6 inclusive, andx is an integer of from 0-2 inclusive.

6. Organosiloxanes consisting essentially of polymeric units of theformula Ptzsi omomofi 0 o-onoHt T where R is a radical selected from thegroup consisting of methyl, ethyl, and phenyl radicals and x is aninteger of from 0-2 inclusive.

7. An organodisiloxane of the formula n sio where R is a monovalenthydrocarbon radical and y is an integer of from O-3 inclusive.

9. Copolymeric organosiloxanes consisting essentially of polymeric unitsof the formula /OGH2 (OHfl)zSi CHQCHEOH 3-1: O-CHCHs 2 where x is aninteger of from 0-2 inclusive, and units of the formula where R is aradical selected from the group consisting of methyl, ethyl and phenylradicals and y is an integer of from 0-3 inclusive, the average value ofy in said copolymer being from 0.5 to 3 inclusive.

References Cited in the file of this patent UNITED STATES PATENTS2,588,083 Burkhard et al. Mar. 4, 1952 2,684,373 Patrick July 20, 19542,695,318 Thiele Nov. 23, 1954 UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION Patent No. 2,846,448 August 5, 1958 John L. Speier It isherebjr certified that error appears in the-printed specification of theabove numbered patent requiring correction and that the said LettersPatent should read as corrected below.

Column 3, line 16, for "contain not only" read contain only -----5column 4, line 16, the formula should read as shown below instead of asin the patent column 8, line 45, the formula should appear as shownbelow instead of as in the patent Signed and sealed this 11th day ofNovember 1958, (SEAL) Attest:

ROBERT C. WATSON Attesting Officer Commissioner of Patents

1. AN ORGANOSILICON COMPOUND SELECTED FROM THE GROUP CONSISTING OF (1)COMPOUNDS OF THE FORMULA